Attach diff. annotation to hashdigest element

(cherry picked from commit 9785838b69df80306d54bc795507740de72dd363)

Conflicts:
	python/Objects.py
Adjust a few debug messages

(cherry picked from commit fa1cf6338ce264e50cec85381d8f5d1e8ba276dc)
Correct summary counts for differential DFXML

(cherry picked from commit 6acdf09211465f9c8df96421651bbb4395acd002)

Conflicts:
	python/summarize_differential_dfxml.py